KX Riders

Maintenance & Technical => KX250 / KX125 => Topic started by: KawasakiRipper on October 23, 2014, 09:30:47 AM

Title: KX 250 Problems! Please help!
Post by: KawasakiRipper on October 23, 2014, 09:30:47 AM
Hello guys, i just put a new pro X piston kit in 1998 kx 250, it has tons of compression now and idles fine but when I get on and  ride it as soon as I hit the gas, the bike bogs and dies. Also when I was looking though the oil glass it looked as if the oil was bubbly? Any help would be greatly appreciated! Thanks guys

http://i72.photobucket.com/albums/i197/Smallz700R/WP_20140710_0021_zps69791c7d.jpg

Title: Re: KX 250 Problems! Please help!
Post by: Foxx4Beaver on October 23, 2014, 09:41:00 AM
did you check the piston to cylinder clearance when you put it together?

the oil isn't grey or milky is it?
Title: Re: KX 250 Problems! Please help!
Post by: KawasakiRipper on October 23, 2014, 09:44:54 AM
yeah well i sent the piston and cylinder to millenium tech, i just changed the oil and started it if I remember correctly the oil after 5 minutes of running was bubbly and kinda gray instead of clear,? Thanks bud
Title: Re: KX 250 Problems! Please help!
Post by: KawasakiRipper on October 23, 2014, 09:50:55 AM
i just went and checked it and its clear and to the top of the sight glass, its just depressing because before i rebuilt the top end this bitch was soo fast. Its sad
Title: Re: KX 250 Problems! Please help!
Post by: Foxx4Beaver on October 23, 2014, 09:53:26 AM
try pullin the plug out right after it dies when you gas it...and see if it's wet or dry.

is the case vent clear and breathing?
Title: Re: KX 250 Problems! Please help!
Post by: KawasakiRipper on October 23, 2014, 10:03:31 AM
Here is pick of spark plug sir, I didnt get there fast enough to see if it was wet, looks kinda wet, looks brand new almost and it idles fine but as soon as I start moving its bogs and dies. What do you mean about case vent sir?

http://i72.photobucket.com/albums/i197/Smallz700R/WP_20141023_0031_zps28691a6b.jpg
Title: Re: KX 250 Problems! Please help!
Post by: Foxx4Beaver on October 23, 2014, 10:08:51 AM
What do you mean about case vent sir?

there should be a breather hose on top the case, it's a vent hose, it should be just behind the kick starter, or very close to the kick starter.
Title: Re: KX 250 Problems! Please help!
Post by: KawasakiRipper on October 23, 2014, 10:23:34 AM
Sorry sir im a bit confused, do you see the hose in the pic

---> http://i72.photobucket.com/albums/i197/Smallz700R/WP_20141023_0041_zps05122610.jpg
Title: Re: KX 250 Problems! Please help!
Post by: Foxx4Beaver on October 23, 2014, 10:27:25 AM
no son, behind the kickstarter coming out of the engine case.....
Title: Re: KX 250 Problems! Please help!
Post by: KawasakiRipper on October 23, 2014, 10:34:10 AM
Am I missing a part or something sir? She starts and idles but dies when I ride it, Here is another pic behind the kicker----------> http://i72.photobucket.com/albums/i197/Smallz700R/WP_20141023_0051_zpsf1af8810.jpg
Title: Re: KX 250 Problems! Please help!
Post by: Foxx4Beaver on October 23, 2014, 10:39:49 AM
wow...you have no idea what's what huh?...yeah, I can see the hose behind the kicker in the pic...whether it's breathing or not, I have no idea, you'll have to figure that out.
put your hand just behind the kick starter on the case, you'll find the hose.
other than that...I can't explain it any simpler, best of luck! 

maybe another member could be kind enough to post a pic of the case vent...I would, but neither of my bikes are here at the moment.
Title: Re: KX 250 Problems! Please help!
Post by: KawasakiRipper on October 23, 2014, 11:03:29 AM
Ok thanks sir, so uh just try to make sure its not clogged?
Title: Re: KX 250 Problems! Please help!
Post by: Foxx4Beaver on October 23, 2014, 11:07:28 AM
correct...and make sure its routed nice and free of kinks.

does it smoke excessively when it's running?
Title: Re: KX 250 Problems! Please help!
Post by: KawasakiRipper on October 23, 2014, 11:18:52 AM
Smokes soooo much! And i even drained the gas and mixed an exact ratio of 32:1 with premium gas and it still smokes out the whole neighborhood! it never used to do this, Thanks guys
Title: Re: KX 250 Problems! Please help!
Post by: Foxx4Beaver on October 23, 2014, 11:28:03 AM
clutch side crank seal :cry:
Title: Re: KX 250 Problems! Please help!
Post by: KawasakiRipper on October 23, 2014, 11:29:47 AM
Dang thats what I have been told lately may be the problem, Do i have to split the case for that?
Title: Re: KX 250 Problems! Please help!
Post by: KawasakiRipper on October 23, 2014, 11:37:50 AM
Is this what I would order?

--->http://www.bossbearing.com/Main-Crankshaft-Bearing-and-Seal-Kit-p/db-779.htm?gclid=CjwKEAjwzqKiBRCAydTZzOLi9CISJACm3irWXX1tLLB-QYh5cqrL_kd6Vnbk_6LxgaV_tOrDd_2mbxoCOXTw_wcB&click=2537&utm_source=googlebase&utm_medium=shoppingengine
Title: Re: KX 250 Problems! Please help!
Post by: Foxx4Beaver on October 24, 2014, 10:55:41 PM
Dang thats what I have been told lately may be the problem, Do i have to split the case for that?

Is this what I would order?

--->http://www.bossbearing.com/Main-Crankshaft-Bearing-and-Seal-Kit-p/db-779.htm?gclid=CjwKEAjwzqKiBRCAydTZzOLi9CISJACm3irWXX1tLLB-QYh5cqrL_kd6Vnbk_6LxgaV_tOrDd_2mbxoCOXTw_wcB&click=2537&utm_source=googlebase&utm_medium=shoppingengine

yes the motor will have to be torn down...and yes those bearings and seals would work...but Cometic seals would be better.